Automatic cut-out



(No Model.) 3 SheetsSheet 1.

G. A. ROLPE.

AUTOMATIC GUT-OUT. No. 580,957. Patented Apr. 20, 1897.

oumo. wasnmumw u c (No Model.) 3 Sheets-Sheet 2.

C. A. ROLFE. AUTOMATIC GUT-OUT.

Patented Apr. 20, 1897.

UNITED STATES Partisan r @rrrcn.

CHARLES A. ROLFE, OF CHICAGO, ILLINOIS.

AUTQIVEATIQ CUT-GUT.

SPECIFICATION forming part of Letters Patent No. 580,957, dated April20, 1897.

Application filed July 16, 1896. erial N0. 599, l04. (N0 model.)

To all whom it may concern:

Be it known that I, CHARLES A. ROLFE, a citizen of the United States,residing in Chicago, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Automatic Out Outs, ofwhich the following is a specification.

My invention relates to that class of devices which are designed toprotect electrical instruments and machines, especially the moredelicate appliances employed for signal ing purposes, from thedestructive effects of lightning and of currents of greater strengththan those which it is intended they should receive.

To secure such protection, my invention contemplates shunting orbridging the instrument by connecting together the conductors leading toand from the same when the current passing in the operating-circuitbecomes greater than the construction of the instrument would safelywarrant.

My invention further contemplates the complete removal of the instrumentfrom the circuit by disconnecting it entirely from the branch or shuntinto which the connection across its terminals places it simultaneouslywith the formation of such branch or shunt. The advantages of such anarrangement are obvious, for by it the instrumentis efficientlyprotected from danger by being disconnected entirely from theoperating-circuit the instant the current therein becomes too great forits safety, while at the same time the continuity of theoperating-circuit is preserved by the simultaneous bridging of theinstrument, or, to be more accurate, by the bridging of the break causedby the disconnection and consequent removal of the instrument from theoperating-circuit. The instrument is thus saved and the endlessannoyance and trouble caused by an open operating-circuit is avoided.For instance, in case there should be a number of instruments on thecircuit and only one becomes affected by an unduly strong current it isevident that the utility of the circuit is not destroyed by thedisconnection of such instrument. In case all the Hence it isunnecessary to replace all the instruments before rendering the lineoperative.

My invention further contemplates placing a condnoting-terminal having aconnection with the ground in close proximity with a portion or portionsof the operating-circuit, whereby lightning drawn to the latter may leapor are across the narrow intervening air-space and escape to the earth.The i11- vention also contemplates the employment of this groundedconductingterminal to connect the operating-circuit across the terminalsof the instrument when such connection becomes desirable.

All the previousl vmentioned advantages are thus procured, with theadditional ones, first, that a very convenient arrangement is madepossible for bridging the instrument, and, second, that should theatmospheric conditions be such that the lightning upon the line shouldrefuse to leap the air-space to the grounded terminal it will operatethe device to throw out the instrument and also ground both sides of theline by reason of the 0011- nection which the grounded terminal formsacross the terminals of the instrument.

In the device more particularly described hereinafter for carrying outmy invention a couple of conductors which are included in theoperating-circuit are arranged adjacent to one another, and a thirdconductor is situated between the two, normally out of contact withboth, but having a tendency to move into contact with and therebyestablish connection between the same. This third conductor is desirablyplaced in very close proximity with those on either side of it and isconnected with the ground. The adjacent surfaces of the conductors arealso desirably made of large area, whereby the tendency of any lightningdrawn upon the line to pass from the pair of conductorsincluded thereinto the third conductor or grounded conducting-terminal is perceptiblyincreased. This grounded terminal is held normally away from. the pairof circuit-conductors and is automatically released when the current inthe circuit becomes unduly great. Any one of a variety of appliancescould be employed to release the same, but as a matter of furtherimprovement I prefer to use for this purpose a thermal cut-out devicefor which I have obtained Letters Patent of the United States No.538384;. This device consists,essentially, in a movable holder for theterminals of a hi ghresistance wire, a suitably-held mass of i'nsi blematerial, and a spring which is normally held under tension and whichtripped or released by the fusion or softening of said mass, the resultof thus releasing the spring being that it will operate to cause thebodily removal of the highresistance wire from the circuit. Suchacut-out is preferably included in the operating-circuit between theinstrument and the previously-mentioned pair of conductors, an d isarranged so that the operation of its spring releases also the thirdconductor or grounded terminal. By such arrangement the circuit is notonly bridged around the instrument, closing and making continuous thesame, but it is also broken and entirely disconnected from theinstrument by the throwing out of the high-resist.- ance portions ofsaid thermal cut-out device, and the line is grounded by the contactwhich the grounded terminal makes with the pair of conductors.

In the accompanying drawings, Figure 1 is a plan of a device embodyingmy invention. Fig. 2 is a section of the same on line 2 2 in Fig. 1.Fig. 3 is a section on line 8 3 in Fig. 1. Fig. i is adetail viewillustrating the method of arranging the high-resistance wire inconnection with the mass of fusible material. Fig. 5 is a plan of amodified form of the device, and Fig. 6 is a section on line 6 6 in Fig.5. Fig. 7 shows a modified arrangement for retaining the spring intension. Fig. 8 is a diagrammatic view of an alternative method ofconnecting up the device.

The device is conveniently mounted ona base A, of non-combustibleinsulating material. Upon this base are mounted the plates B B, whichare made of suitable conducting material and are placed at a slightangle with one another. Each plate is provided with a couple ofbinding-posts I), whereby the, are included in either side of thecircuit leading to the instrument to be protected. Between these platesis a third plate Qwhich is mou nted upon the base A to permit itslongitudinal movement, by providing it with the slots 0, through whichthe screws D are passed and secured to said base. The sides of thisplate 0 are inclined or tapered to be parallel with the adjacent sidesof the plates l3 l3, whereby the downward motion of the plate G willcause it to contact at all points along its sides with the plates l5 l3.This arrangement-namely, a couple of conductorsincluded in the circuitand a third conductor normally disconnected from both, but capable ofbeing moved into contact with the same-is greatly preferred bynie,although the same result may evidently be accomplished by having thethird conductor connected with one of the other two and arranged to beconnected with the other one also, it being evident that the essentialfeature is to have the third conductor disconnectedfrom at least one ofthe other two and capable of connectingthe same. As a means forproducing a tendency on the part of the plate C to move into contactwith. the plates 1- 13, I have shown a coil-spring .ll surrounding thespindle F, with which the plate 0 is provided, which is retained intension by being confined between the plate 0 and the bracket ll,secured to the base A. C is also provided with a binding-post c, towhich is attached the conductor G, which is understood to make suitableconnection with the earth.

The movable plate 0 may be retained out of contact with. the plates l3l3 and permitted to move toward the same by any one of a number ofsuitable devices. I prefer, however, to use in this connection thethermal cut-outhereinbeiere mentioned as patented by me. This device isshown in Figs. 1, 2, and 23, and is constructed, lnrielly, as follows: Aplate J, of nonconducting material, is provided with metal end pieces j,which are held within and in contact with a pair of spring-metal jaws K.A fine wire L, of high resistance, bridges the space between the metalend piecesj on the noncon d uctingplate and is wrapped upon the shank ofa hoop or loop iii, which is then embedded in a mass N of substance ormaterial which easily softens or becomes friable when subject to amoderate degree of heat. The stem portion of this fusible button extendsthrough an eye on the non-conducting plate, said eye being arranged tosupport the mass N (which for convenience may be termed a fusiblebutton) and to further provide a stop against which the head or largerportion. of the button. is normally held by the tension of the spring P,secured upon the non-conducting plate and having one of its 2Llll]S]) inengagement with the hoop or loop M. The metal jaws K, the metal platesj,held by said jaws, and the wire l; are all included in the circuit.\Vhen, therefore, an unduly strong current comes in the circuit, theheat developed in the fine wire will fuse the button and therebyliberate the hoop or loop to which said wire is attached, and thereuponthe spring-arm engaging the hoop or loop will. move in a direction tocause a sudden strain. upon and a consequent rupture in the fine wire,which will usually break the circuit. For reasons pointed out in saidpatent, however, a second spring Q is arranged upon the base A. and isprovided with an arm (1, which when free will extend upwardly or awayfrom the base. The spring is, however, normally under tension, and tosuch end its arm (1 is held down by a catch a and arranged to extendunder the non-conducting plate J. This plate J is removably held incircuit by the jaws K, and hence when the spring-arm is released fromthe catch a it will fly up, and in so doing will engage the plate .l andthrow the same out of engagement with the jaws, an d thereby break thecircuit. The spring Q is released from the catch (L primarily by themelting or The plate softening of the fusible button, and to such endthe arm of spring Q is held by catch a in position adjacent to the arm pof spring P and in the path traversed by said arm when the hook or loopM is released. hen this latter operation occurs, the arm 1) of spring Pwill strike and throw the arm q of spring Q out of engagement with catchCL, and there upon the spring-arm will spring upwardly and kick theplate J, which carries the wire L, out of the spring-jaws, and therebybreak the circuit.

The spring Q is conveniently situated upon the base A with its free endof the arm q against the plate 0, and thereby serves as a stop orabutment to maintain the latter out of contact with the plates B Bagainst the action of the spring E. A single plate J, constructed asdescribed, could be employed to release the springarm q, but I prefer touse two, placing one on each side of the circuit with reference to theinstrument to be protected and arranging both to operate to release thespring-arm q. This arrangement insures the complete disconnection of theinstrument by removing a portion of the circuit on either side thereofand also has the advantage that should either one of the springs P oroperating parts connected therewith become inoperative the other willvery likely be still perfect and operative, and as the operation ofeither one will serve to release the spring-arm q the result will be aseffective as if both were in good working order.

From the foregoing it is evident that I may vary the construction andarrangement of the thermal releasing mechanism, the essential featuresbeing a spring, as Q, serving as a stop for the plate 0, and a mass offusible material arranged to release this spring Q when fused or melted.It will be further evident that the coil of fine wire of high resistanceis removablyheld in circuit and is contained in the mass of fusiblematerial, and also that when the spring, as Q, which is normally held intension by means of the fusible mass, is released by the fusion orsoftening of said mass it operates in a direction to throw out ofcircuit the support to which the ends of the fine wire are attached.

In place of a thermal cut-out for automatically releasing the plate 0, Imay employ a number of other devices, one of which is shown in Figs. 5and 6. In this arrangement I include in the circuit an electromagnet, asR, which is conveniently mounted on the bracket secured to the base A,and which is inactive under the influence of the normal current passingin the circuit.

An armature S is placed opposite the poles of the magnet R and arrangedto release the plate C when attracted by the magnet, which occurs whenthe current in the circuit becomes unduly great. To this end thearmature S is provided with a rear extension 8,

which is arranged to slide longitudinally in a bearing T, secured to thebase. This rear extension 3 could be set directly against the plate 0,but as a matter of further improvement the spring is interposed, itbeing arranged to serve as a stop or abutment for said plate and held intension by the rear extension 5' of the armature. A couple of movableconductors, as the bars L, are then supported in the contacts 7t" abovethe spring Q, whereby the spring, when released, flies up, and in sodoing permits the plate 0 to come into contact with the plates B B, andalso throws the movable conductors L out of circuit.

From the foregoing, taken in connection with the description of thethermal cut-out, it will be seen that in either case a stop or abutmentis provided for the plate 0, with means for removing the same, and alsothat a spring may be arranged to serve as such stop or abutment and tothrow out from circuit one or more movable conductors when re leased.

With further reference to the conductingplates B B and C, I may statethat I find carbon an exceedingly satisfactory material for theircomposition. hen made of this material and provided with large opposingsurfaces placed in close proximity with one another, the lightning whichmay be drawn upon the line has little difficulty in leaping theintervening air-space to the plate C and thus escaping to the ground.The plates B B do not become charged at such times, as is the case withmetal plates, and consequently there is seldom any disruptive discharge.

As a substitute for the fusible mass N for holding the spring P intension I may employ the arrangement shown in Fig. 7, in which the wireL is composed of an easily-fusible conductor or fusible alloy and islooped about the spring-arm p, passed through the eye 0, and connectedto the end pieces j. The passage of a strong current melts the wire Land releases the spring-arm p.

I find it exceedingly advantageous to arrange the device as shown inFig. 8, including in the circuit a spring held by a mass of fusiblematerial and also one held by a fusible wire. In such case a suddenincrease in the current, which might burn out the high-resistance wireused with the mass of fusible material without producing any noticeableeffect upon the latter, will melt the fusible wire holding the otherspring and thereby operate the device without fail. By thus combiningthe two an instrument will be perfectly protected against bothsneak-curren ts and sudden increases in voltage.

hat I claim as my invention is 1. The combination of a cut-out devicefor removing the instrument from the line; means for connecting the lineacross the terminals of the instrument; and means, operating upon anexcess of current in the line for simultaneously operating both thecut-out device and the connecting means.

2. The combination of a cut-out device for removing the circuit from theline; means of current in the line, for simultaneously actuating all ofsaid instrumentalities, whereby the instrument is automatically cut out,and the line maintained intact and grounded.

4. The combination of a cut-out device comprising a couple of removablesections of circuit-conductor arranged for bodily removal from thecircuit, for removing the instrument from the line; means for connectingthe line across the terminals of the instrument; and means, operatingupon an excess of current in the line, for throwing said removable sections of conductor out of circuit, and also for simultaneously operatingsaid connecting means.

5. The combination of a cut-out device comprising a couple of removablesections of circuitconductor arranged for bodily removal from thecircuit, for removing the instrument from the line; means for connectingthe line across the terminals of the instrument; a spring held normallyin tension and arranged, when released, both to actuate the connectingmeans and to throw said removable sections of conductor out of circuit;and means, operating upon an excess of current in the line, forreleasing said spring.

6. The combination of a cut-out device comprising a couple ofbodily-removable sections of circuit-conductor whereof one removablesection consists of a coil of high-resistance wire, for removing theinstrument from the line; means for connecting the line across theterminals of the instrument; and a mass of fusible material arranged inconnection with the coil of high-resistance wire, and arranged also toeffect simultal'leously both the removal of the removable sections ofconductor and the operation of the connecting means when fused ormelted, as set forth.

7. The combination of a coil of high-resistance wire arranged inconnection with a mass of fusible material; a section of fusible coirduct-or; and mechanical means, for removing the instrument from theline, arranged to be operated either by the softening or melting of themass of fusible material, or bythe fusion of the fusible conductor.

8. A cut-out device comprising a couple of conductors arranged forinclusion in the op crating-circuit on each side of the instrument to beprotected; a couple of removable sections of circuit-conductor betweenthe instrument and the two first-mentioned conductors, whereof oneconsists in a coil of high-resistance wire supported by a mass offusible material, and the other of a length of fusible wire; a thirdconductor arranged to establish connection between said two conductors;and means for effecting the connection of the latter by said thirdconductor, said means being arranged to be operated by the fusion eitherof the mass of fusible material or of the fusible wire, and being alsoarranged to simultaneously throw the removable sections ofcircuit-conductor out of circuit, substantially as set forth.

9. A cut-out device comprising a couple of conducting-platesfa thirdplate situated between the two and arranged to be brought into contactwith the same; a spring tending to bring about such contact, a body offusible material containing a coil of higlrresistance wire which isremovably held in circuit; and a second spring normally held in tensionby the fusible mass and acting to maintain the first-mentioned spring intension and arranged to throw the movable section of circuit-conductorout of circuit, and also to release the first-mentioned spring, when itis liberated by the fusion or softening of the mass of fusible material,substantially as described.

10. A cutout device comprising a couple of adjacent conducting-plates,having their opposing sides inclined to one another; a third taperingplate, situated between the two firstmentioned plates, and arranged tobe brought into contact with the same by a longitudinal movement; aspring tending to bring about such contact; a kicker-spring normallyheld in tension by a catch; a mass of fusible material containinga coilof high-resistance wire which is removably held in circuit; a springheld in tension by the mass of fusible material, and arranged to freethe kicker-spring from the catch when it is liberated by the fusion orsoftening of the fusible mass, and the kicker-sprin g being arranged tothrow the removable section of circuit-conductor out of circuit whenthus released from the catch, substantially as described.

11. A cut-out device comprising a couple of carbon plates, a thirdcarbon plate which has a ground connection, and is situated betweenthetwo first-mentioned plates and arranged to be brought into contactwith the same; a spring tending to bring about such contact; a secondspring normally held in tension, and arranged to resist the action ofthe first-mentioned spring; and a mass of fusible material arranged torelease the second spring when fused or softened, and thereby permit thefirst-mentioncd spring to bring the plates into contact, substantiallyas described.

12. A cut-out device comprising a couple of conducting-plates; a thirdplate situated between the two first-mentioned plates, and arranged tobe brought into contact with the same; a spring tending to bring aboutsuch contact; a second spring normally held in tension and arranged toresist the action of the firstunentioned spring; one or more movableconductors included in the circuit, and arranged to be thrown out oftheir cooperating contacts by the action of the second spring; and meansfor releasing the latter, substantially as set forth.

13. A cut-out device comprising a couple of adjacent conducting-plates,having their opposing sides inclined to one another; a third taperingplate, situated between the two firstmentioned plates, and arranged tobe brought into contact with the same by longitudinal movement; a springtending to bring about such contact; a kicker-spring normally held intension by a catch, and serving to maintain the conducting-plates out ofcontact; a couple of springs normally held in tension, the one bya massof fusible material containing a high-resistance wire which is removablyheld in circuit, and the other by a loop of fusible wire, and botharranged to free the kicker-sprin g from the catch when liberatedthemselves, and the kicker-spring being arranged to throw the removablesection of cir- Quit-conductor out of circuit when thus freed,substantially as described.

1%. In an automatic cut-0ut, the combination of a removable holderprovided with a section of fusible conductor; a spring arranged upon theholder and normally held in tension by a loop formed in the section offusible conductor; and a second spring normally held in tension andarranged to throw the removable holder out of its cooperating contactswhen released, and to be liberated by the first-mentioned spring whenthe latter is released by the fusion of the fusible conductor,substantially as set forth.

CHARLES A. ROLFE.

Witnesses:

A. F. DURAND, RETA M. WAGNER.

